FR2765854A1

FR2765854A1 - Cycle front and rear suspension

Info

Publication number: FR2765854A1
Application number: FR9709129A
Authority: FR
Inventors: Alain Poyet
Original assignee: RHONE ALPES SOUDURE
Current assignee: RHONE ALPES SOUDURE
Priority date: 1997-07-11
Filing date: 1997-07-11
Publication date: 1999-01-15
Anticipated expiration: 2017-07-11
Also published as: FR2765854B1

Abstract

<P> The front and rear suspension devices for cycles are characterized in that damping means (M1 - M2) are used integrated in the tubes constituting the frame (C), namely: the fork tubes ( 23 - 24) for the front suspension and the horizontal tube (T1) for the rear suspension; said damping means being able to move inside the tubes under the effect of the weight of the user and terrain accidents, being for this, connected to the rear wheel by an articulated assembly (E) connecting with the bases (B) and the seat stays (H) for the rear suspension, and connected to the ends (26 - 27) of the fork tubes and to a brake support (39 - 41) for the front suspension. </P>

Description

FRONT AND REAR SUSPENSION DEVICE FOR CYCLES
Bicycles equipped with suspension means have been known for a long time either at the front at the head tube or at the fork, or at the rear combined with the seat post, the seat stays or even between elements of the frame.

As a rule, these means were rudimentary and essentially composed of unsightly springs and brutal reaction.

Recently, just as basic suspensions have been developed, for example where the springs have been replaced by elastomer blocks, which has brought an improvement in comfort. However, this type of suspension is of very limited use, in particular they apply only to certain types of leisure bicycles such as ladies' bikes or low-end mountain bikes.

Recently, mountain bikes have also been fitted with front and / or rear suspensions of the coil spring type and / or cylinders connected to the fork for the front and to certain elements of the frame for the rear.

These shock absorbers are most often heavy and bulky and destroy the geometry of the frame, therefore are aesthetic.

On the other hand, they are neither suitable for every kind of mountain bikes on the market today, nor suitable for all body shapes, because they are not adjustable during use, but tared at manufacturing.

It is therefore in order to overcome these drawbacks that the front and rear suspension devices according to the invention have been designed, the elements of which are judiciously arranged and combined with one another, offer significant comfort and efficiency while retaining geometry on the bicycle. relatively classic due to the discretion of the devices.

To solve the problem of the bulk of the known suspension devices, damping means are used integrated in the tubes constituting the frame, namely: the fork tubes for the front suspension and the horizontal tube for the rear suspension; said damping means being able to move inside the tubes under the effect of the weight of the user and terrain accidents, being for this purpose connected to the rear wheel by an articulated assembly for connection with the bases and the struts of the frame which are also articulated, as regards the rear suspension, and connected to the ends of the fork tubes and to a brake support for the front suspension.

To solve the problem of adapting to the weight of the user, his morphology and the type of use of the bicycle, the shock absorbing means integrated in the tubes of the frame, as well as the articulated assembly for connection with the rear wheel. are able to be adjusted in position in their housing and adjustable in terms of the setting of the hardness.

These characteristics and others will become apparent from the following description.

To fix the subject of the invention illustrated in a nonlimiting manner in the figures of the drawings where:. Figure l is a schematic view illustrating a bicycle frame
fitted with suspension devices according to the invention and shown in the position of
rest.

. Figure 2 is a view similar to Figure l showing the devices
suspension in maximum compression position.

Figure 3 is a top view corresponding to Figure 1.

. Figure 4 is a longitudinal sectional view illustrating a first form of
realization of the shock absorbers of the rear suspension integrated in the tube
horizontal and shown in the rest position.

. Figure 5 is a view similar to Figure 4 illustrating the damping means
in the maximum compression position.

. Figure 6 is a longitudinal sectional view illustrating another form of
realization of the rear suspension damping means shown in
rest position.

. Figure 7 is a partial sectional view showing an inflation valve of a
chamber of the damping means according to FIGS. 4 and 5.

FIG. 8 is a view illustrating one of the arms of the articulated connection assembly between
the damping means and the frame, with in cross section the constitution of the mounted pivot
on the frame.

FIG. 9 is a sectional view taken along line 9-9 of FIG. 8.

Figure 10 is a view illustrating the adjustable connection between the arms and the connecting rods
the articulated assembly.

. Figure 11 is a longitudinal sectional view illustrating the damping means
front integrated in the fork tubes.

Figure 12 is a sectional view taken along line 12-12 of Figure 11
illustrating the connection between the damping means integrated in the tubes of
fork and brake caliper.

In order to make the object of the invention more concrete, it is now described in a nonlimiting manner illustrated in the figures of the drawings.

The illustrated bicycle frame is of the all-terrain type which constitutes the more particularly intended application of the invention. However, it is entirely possible to adapt the suspension devices to road, touring or racing bicycles.

The frame (C) comprises in known manner, a so-called horizontal tube (T1), a seat tube (T2), a down tube (T3) and a steering tube (T4) through which the rod (F1) passes. fork (F).

The tubes (T2) and (T3) are connected to a bottom bracket (BP), and an arch (A) connects the tubes (T2) and (T3) above the bottom bracket.

According to the invention, the complementary elements of the frame, that is to say the bases (B) and the shrouds (H), the free ends of which receive the rear legs (P1), are not rigidly fixed to the box bottom bracket and at the top of the seat tube, but are articulated on the one hand to a yoke (1) integral with the bottom bracket for the bases, and to a movable assembly (E) for connection with the damping means thus constituting the rear suspension.

Said assembly (E) comprises two curved and parallel connecting rods (2) which are articulated at one of their ends on a pivot (3) which is mounted in a sheath (4) made integral with the seat tube (T2) and the hoop (A). As illustrated in FIGS. 8 and 9, the pivot (3) is composed of a stepped axis (3a) with guide grooves (3a) for the connecting rods (2) and around which are housed two half-shells (3b) which are locked in rotation in the bottom bracket by any means such as needle screws (3c).

Between the axis (3a) and the half-shells (3b) are interposed four blocks (3d) of elastomer thus acting as a complementary damper.

At the free ends of two connecting rods (2) are articulated by an axis (5), the shrouds (H), while in their middle part or approximately, the connecting rods have two axes (6) on which the free ends are freely articulated two curved and parallel arms (7), the opposite ends of which pass on either side of the horizontal tube (such) to which they are connected by an axis (8) passing through two diametrically opposite openings (T1A) produced on the tube (T1 ).

Note that the relative positions of the arms (7) and the connecting rods (2) can be adjusted.

For this and according to a nonlimiting embodiment, the connecting rods (2) have a lumen (2a) for cooperation with the central screw (3e) of the pivot, while the arms (7) have at their free end several orifices (7a ) of cooperation with the axes (6) connecting to the connecting rods.

The axis (8) cooperates with the damping means proper (M1 - M2) integrated in the horizontal tube (T1).

More particularly, as illustrated in FIGS. 4 and 5, the axis (8) passes through a long piston (9) with sealing members (9a) at the two ends (9b - 9c). The end (9b) receives a threaded rod (10) carrying a nut (11) allowing the positioning adjustment of the piston (9). An elastomer washer (12) is connected to said nut to absorb the shock back against the seat tube (T2).

At the opposite end (9c), the piston receives an elastomer sheath (13) carrying at the other end a small double piston (14). In the bore of the sleeve (13) is engaged an elastomer cylinder (15) of length less than that of the sleeve (13).

Finally, a coil spring (16) bears at rest against the double piston (14) and a single piston (17) applied against the steering tube (T4).

As can be seen in FIG. 5, when, under the effect of the weight of the user and the reaction of the ground, the arms (7) and the connecting rods (2) moving (FIG. 2), cause the sliding of the piston (9) by the axis (8), this against the spring (16) which is compressed, at the end of the stroke, beyond the maximum compression of the spring, this is then the damping phase by compression of the sleeve (13) then of the cylinder (15) made of elastomer.

As a variant, and as illustrated in FIG. 6, the damping means are different in the sense that if there is a long piston (18) secured to the axis (8) connecting with the connecting rods (2), the rod threaded (10) and its nut (11), as well as the stop ring (12), on the other hand, on the other side, a nose (18a) of the piston receives externally a coil spring (19) of which the other end rests against a commercial hydraulic cylinder (20) whose front rod (20a) can, under the advance of the piston (18), penetrate into a bore (18b) of the nose with damping at the end of the stroke after pressing against the bottom of said bore.

In this case, it is possible to adjust the damping hardness by moving the jack using an external button (21) secured to the jack body and traversing a helical light (T1B) of the horizontal tube (T1).

With the damping means described in Figures 4 and 5, it is also possible to adjust the hardness of the damping. For this, as can be seen in FIG. 7, the chamber delimited by the pistons (9 and 14) can be placed in communication with the outside by a conventional inflation valve (22). So, when we send air into this chamber, we increase the compression effect, so we get a faster return. On the contrary, if we decrease the pressure in the chamber, we will obtain a less brutal damping and therefore a softer return.

The front suspension illustrated in FIGS. 11 and 12 is based, with regard to the damping means on the same principle, that is to say with members integrated in fork tubes (23 - 24) fixed to a head of profiled fork (25) receiving the fork stem (fol), while the lugs (P2) for fixing the axle-wheel hub are fixed at the end of the tubes (26 - 27) sliding tightly in the tubes fork (23 - 24).

Inside each tube (26 - 27) is housed a sheath (28) whose hollow rear part receives an elastomer ring (29) compressed by the head (30a) of a threaded rod (30) screwed into a fixed sheath (31) housed in each fork tube (23 24) at their end cooperating with the fork head.

Between the fixed sheath (31) and the movable sheath (28) are disposed a coil spring (32) and an elastomer ring (33) separated by a support washer (34), while, on the rod (30 ), is placed a shouldered nut (35) secured to an elastomer cylinder (36) which, during compression of the spring acts as a shock absorber by pressing against the washer (34).

Note that the threaded end of the rod (30) receives a knurled actuating nut (37) for adjusting the position of the rod, therefore adjusting the hardness of the damping means.

The movable sheath (28) has along two orthogonal axes, spacers (38) which can slide in corresponding slots (23a - 24a) formed in the fork tubes along their opposite sides and at the rear. These spacers are capped by a brake-support bracket (39) fixed to the sheath (28) by screws (40); the brake caliper (41) being fixed at (39a) on the bracket.

The advantages emerge clearly from the description, it is emphasized again: the numerous possibilities for adjusting the suspensions in terms of their hardness and their action with easy balancing between the front and the rear thanks to the position adjustments of the assembly (E ), to the position adjustments of the damping means, thus making it possible to adjust the ground clearance, to tilt more or less from the front or from the rear, to obtain soft and wide suspensions, or stiff and limited according to the needs or according to the morphology of the user.

Claims

-1- Front and rear suspension devices for cycles, characterized in that damping means (M1 - M2) are used integrated in the tubes constituting the frame (C), namely: the fork tubes (23 - 24) for the front suspension and the horizontal tube (T1) for the rear suspension; said damping means being able to move inside the tubes under the effect of the weight of the user and terrain accidents, being for this, connected to the rear wheel by an articulated assembly (E) connecting with the bases (B) and the seat stays (H) for the rear suspension, and connected to the ends (26 - 27) of the fork tubes and to a brake support (39 41) for the front suspension.
-2- Suspension devices according to claim 1, characterized in that the damping means (M1 - M2) integrated in the frame tubes, as well as the articulated assembly (E) connecting with the rear wheel, are capable of being adjusted in position in their housing and one relative to the other, in order to adjust on demand the deflections and the setting of the hardness.
-3- Suspension devices according to claim 1, characterized in that the articulated assembly (E) of the rear suspension device is composed of two pairs of rods (2) and arms (7) curved and parallel to each other; the arms (7) are freely articulated at one end on an axis (8) slidably mounted relative to the horizontal tube (T1) of the frame equipped with lights (T1A), and connected to the damping means (M1) integrated in said tube, while their opposite end cooperates with the connecting rods (2) by pins (6) located substantially in the middle part of said connecting rods which are themselves mounted for free rotation at one end, on a pivot (3) fixed on a fixed sleeve of the seat tube (T2) of the frame, while at the other end, said connecting rods are articulated freely by an axis (5), on the shrouds (H) of the frame themselves connected, by lugs (Pl) wheel mounting, with the bases (B) articulated on a yoke (1) secured to the bottom bracket (BP) of the frame.
-4- Rear suspension device according to claim 3, characterized in that the pivot (3) of articulation of the assembly (E) is composed of a stepped axis (3a) with guide grooves (3al) for the connecting rods (2) and around which are housed two half shells (3b) indexed in rotation relative to the bottom bracket (BP).
-5- Device according to claim 4, characterized in that, between the shouldered axis (3a) of the pivot and the half-shells (3b), are interposed four blocks of elastomer (3d) acting as a complementary damper.
-6- Rear suspension devices according to claims 2 and 3 together, characterized in that the articulated connection (6) between the connecting rods (2) and the arms (7) is adjustable by the production of several orifices (7a) of the arms to cooperate with the connecting rods (2) by the axis (6).
-7- Rear suspension devices according to claims 2, 3 and 4 together, characterized in that the connecting rods (2) are adjustably connected on the stepped axis (3a) by lights (2a) formed at the ends of the connecting rods and cooperating with a central screw (3e).
-8- Rear suspension devices according to claim 1, characterized in that the damping means (M1) integrated in the horizontal tube (T1) consist successively of a long piston (9) connected to an axis (8), a sheath made of elastomer (13) bearing against one end (9c) of the piston and against a double piston (14) and into the bore of which is engaged an elastomer cylinder (15) of length less than the length of the sheath (13) and , finally a coil spring (16) interposed between said double piston (14) and a single piston (17) bearing against the steering tube (T4) of the frame.
-9- Rear suspension devices according to claim 1, characterized in that the damping means (M1) integrated in the horizontal tube (T1) of the frame, consist successively of a piston (18) connected to an axis (8), a coil spring (19) resting on a shoulder of the piston and centered around a hollow nose (18a) of said piston which can interpenetrate with the rod (20a) of a hydraulic cylinder (20) constituting the damping means.
-10- Rear suspension device according to claims 2, 8 and 9 together, characterized in that the pistons (9 and 18) connecting with the axis (8) are adjustable positioning by a threaded rod system (10) - nut (11) with elastomer stop (12) integral with the end of said pistons.
-11- Device according to claim 9, characterized in that the damping hydraulic cylinder (2à) is adjustable positioning in the horizontal tube (T1) by connection with an external operating means (21) connected to said cylinder and traversing a helical light (T1B) of the tube (T1).
-12- Device according to claim 8, characterized in that, at the level of the chamber delimited by the pistons (9 and 14) and containing the sheath (13) and the elastomer cylinder (15) is installed an inflation valve ( 22) intended to modify the conditions of damping by injection or exhaust of air.
-13- Suspension devices according to claim 1, characterized in that the damping means (M2) of the front suspension integrated in the fork tubes (23 - 24) connected to the fork head (25) are formed to each tube by a piece stack comprising successively, from said head, a fixed sheath (31), a coil spring (32), a support washer (34), an elastomer ring (33), and a movable sheath (28), with internally at its rear end an elastomer ring (29) compressed by the head (30a) of a threaded rod (30) connecting the assembly and which is screwed into the fixed sheath (31), with a shouldered nut (35) secured to a damping elastomer cylinder (36).
-14- Device according to claim 13, characterized in that the movable sheath (28) cooperates, along two orthogonal axes (spacers (38)) passing through corresponding slots (23a - 24a) established on the fork tubes; screws (40) also fixing, for each tube, a brake bracket (39); on said brackets being fixed a brake caliper (41).
-15- Device according to claim 13, characterized in that the damping means (M2) are adjustable in position by an operating nut (37) associated with the threaded rod (30).